Chair frame



FIG. 1 is a perspective view of a chair frame, the broken lines showing the chair seat and chair back are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a front view of the chair frame;

FIG. 3 is a back view of the chair frame;

FIG. 4 is a left side view of the chair frame, with the right side view being a mirror image thereof;

FIG. 5 is a top view of the chair frame; and,

FIG. 6 is bottom plan view of the chair frame.

The broken lines showing the feet in all of the figures are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a chair frame, as shown and described. 